1. Field of the Invention
The invention herein relates to a cable, specifically an improved structure cable providing noise rejection in a wide frequency range.
2. Description of the Prior Art
Two well-known cable structures are a coaxial cable and a twisted pair cable. A coaxial cable usually consists of a core conductor, a dielectric insulator, and a conducting shield, which is usually surrounded by a jacket. The core conductor of a coaxial cable is surrounded by a dielectric insulator, which is surrounded by a conducting shield. A coaxial cable provides the best noise reduction in high frequencies.
In a twisted pair cable, two conductors are wound together. The two conductors typically carry equal and opposite signals, and the noises from the two conductors cancel each other since the two conductors are exposed to similar electromagnetic interference. The best noise reduction in a twisted pair cable occurs in low frequencies.